(define (mysqrt x)
  (define ( good-enough? guess)
    (< (abs (- (square guess) x)) 0.0001))
  (define ( improve guess)
    (/ (+ guess (/ x guess)) 2))
  (define (try guess)
    ( if (good-enough? guess)
    guess
   (try (improve guess))))
  (try 1))
